Metallic ink composition for wick type writing instruments

ABSTRACT

An ink composition or system for writing instruments constructed with a polyester fiber reservoir and a porous oriented fiber nib. This ink system will write on both black and white surfaces. On black surfaces, it will reveal itself as being opaque and metallic almost iridescent in appearance. On white surfaces, a tint of color is observed with distinct flecks of silver. The ink system is composted of water as a carrier, a permanent water-based binder, a colored pigmented permanent water-based dispersion of sub-micron particle size, a unique aluminum dispersion of specific particle size in a special carrier, a humectant, a surfactant that lowers surface tension, an anti-settling additive, a preservative and a base acting as a pH adjuster.

BACKGROUND OF THE INVENTION

The present invention relates to metallic ink based writing instrumentsand, more particularly, to metallic ink compositions for wick typewriting instruments.

Currently, metallic ink writing instruments are enjoying greatpopularity. These are almost entirely in the form of a conventionalstyle marker currently called a valve action marker (see FIG. 1). Fromthe diagram, one can see that this is a complex device involvingelaborate assembly. The valve action marker also involves shaking backand forth and then depressing, or pumping, the nib several times beforeink will come down. As one can see, this is a rather cumbersome process.

Historically, metallic pigments have a large particle size greater than20 microns; therefore, passage through a wick-style marker has not beenpossible. Instead, a valve-action marker is constructed with two steelballs in its ink chamber and a spring mechanism at the front in contactwith the nib or tip. Since the specific gravity of the aluminum pigmentis greater than water, it tends to settle rapidly. This is overcome byshaking back and forth, thereby re-mixing the aluminum particles in theink. The pumping action on the paper forces the large particle aluminumpigments through the tip by applying pressure through the tip, thereby,producing ink and making writing possible.

Related conventional art includes U.S. Pat. Nos. 5,013,543 to Mercado;5,219,560 to Kazuhiro; 5,106,881 to Hiroshi; 4,761,277 to Valdes;4,872,905 to Bourne and 4,604,139 to Shoi, the contents of which areincorporated by reference herein. Regardless, the prior art has notdelivered to date a wick-style marker which can deliver metallicpigments, i.e. inks, in writing instruments. As a result, metallic inkwriting instruments have been more expensive, more complex to build andmaintain, less reliable and have not fully realized their potential.

SUMMARY OF THE INVENTION

The general object of the present invention is to provide metallic inkcompositions that work reliably in wick type writing instruments.

The foregoing and other objects of the invention are realized by thepresent invention which shows how one can overcome the aforementioneddrawbacks of the prior art using a comparatively inexpensive wick-stylemarker that works by capillary action eliminating a costly assemblyprocess.

The objects of the invention are achieved by mainly utilizing:

1. A small particle size aluminum dispersion less than 12 microns;

2. an anti-settling agent to keep aluminum flakes in suspension;

3. a densely packed highly porous polyester fiber filler;

4. a highly porous oriented polyester fiber nib with many channels;

5. a non-volatile humectant; and

6. a sub-micron colored pigmented dispersion.

This invention will work for a conventional simple wick-style markerthat carries a cylindrical shaped reservoir (filler) that absorbs theink and transports it to a porous oriented fiber nib that feeds on thefiller by capillary action (see FIG. 2).

The invention results in a minimum of metallic particles settling out.The marker can be stored either vertically or horizontally; overcoming atraditional problem associated with pigmented ink systems. This wick-inksystem, when filled into the writing device (FIG. 2), will also lay-downa thick opaque line capable of being seen on both black and whitesurfaces.

Traditional inks that work with pens (FIG. 2) cannot write on blackpaper since they are translucent, therefore, this market has beenoccupied by the valve-action marker of FIG. 1 which permits the flow oflarge particle size pigments. This invention solves this problem in awick-style writing instrument (FIG. 2) that is user friendly and muchsimpler, not to mention a cheaper alternative.

The present invention is based on the startling discovery that based onthe disclosed, specific ink formulation, a writing instrument can bemade that carries a cylindrical shaped reservoir which feeds into afiber nib by capillary action and remains for extended periods withoutsettling out or blocking the nib or tip. This invention also eliminatesthe use of an expensive valve type marker.

Thus, an object of the invention is that a single wick-type pen can beused to write on both black and white surfaces and achieve a metallicalmost iridescent appearance.

Another object of the invention is a pen that may possibly be used fordecorative poster work on both black and white surfaces.

A further object of the invention is the ability to write on human skinto achieve decorative effects similar to temporary tattoos, with anintense opaque metallic look, and washable with soap and water.

Still further, an object of this invention is to attain, by changing thepermanent binder to a temporary one, a damp erase or dry erase writinginstrument that can be made to write on black and white melamine,porcelain and all non porous boards.

The invention composition includes water as a carrier, an acrylic resinin solution as a binder although a polyvinylpyrrolidone polymer can besubstituted to make temporary inks, a pigmented dispersion as a coloringagent, a unique aluminum dispersion of particle size 1 to 12 microns, asurfactant to reduce surface tension, an anti-settling agent to suspendaluminum particles along with a preservative, and a pH adjuster in theform of an amine.

The components of the writing instrument utilized in this invention areof some importance. The polyester filler, or reservoir chosen, must bedensely packed and porous to allow flow of aluminum particles and at thesame time keep settling to a minimum. Polyester fiber is chosen becauseit is non-reactive and very porous. The tip, or nib, of the writinginstrument must be a porous, oriented polyester nib that has manychannels to allow aluminum pigments to pass freely. Many other types offibers will filter the aluminum and only allow the colored pigment topass through, thus creating a non-metallic appearance.

One additional detail should be noted about this invention. Dyes are notused in this composition. This is because dyes wash away easily, they donot provide bonding to the aluminum pigments and are more of an outlineas described in U.S. Pat. No. 4,604,139.

This invention utilizes a permanent and semi-permanent opaque metallicink, which may display iridescent qualities depending on the surfacewritten on—black or white.

Other features and advantages of the present invention will becomeapparent from the following description of the invention which refers tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 diagrammatically illustrates a conventional valve action inkdispensing writing implement.

FIG. 2 illustrates a conventional, wick-style writing implement.

DETAILED DESCRIPTION OF THE INVENTION

The present invention illustrates the considerable ease and convenienceof an ink system in a simple wick type writing instrument (FIG. 2),compared to the complexity of conventional valve-action markers (FIG. 1)that are currently used to deliver metallic inks.

This invention is accomplished by providing an aqueous one-phase inkcomposition having a viscosity of 5 cps to 10 cps at 25° C. with a pH of7.5 to 8.5 suitable for use in a wick-style writing instrument with aporous oriented fiber nib.

This ink system contains an aluminum pigmented dispersion of no greaterparticle size than about 12 microns, a sub-micron pigmented coloredaqueous dispersion to impart a tint and contribute to permanency, ananti-settling agent to keep aluminum particles from settling out, and abinder to bind the aluminum pigments together and to impart adhesion,water resistance, gloss, and permanency to different surfaces.

In addition to the foregoing important ingredients, this ink system maycontain other additives including a preservative, a surfactant to reducesurface tension, a pH adjuster in the form of an amine, and a rheologymodifier such as a starch or clay.

As noted before, one of the important aspects of the present inventionis the particle size of the aluminum pigments. If the particle size istoo large, greater than 12 microns, they will not flow through thepathways of the filler and nib. This is one of the main reasons whymetallic inks have been confined to be used only in valve markers (FIG.1), which is essentially a free-flowing system, and the pumping actionimparts pressure on the aluminum particles forcing them through the nib.

The present invention solves the problem by using a carefully monitoredparticle size aluminum dispersion, along with a customized filler ofhigh density with many pathways, and a highly porous oriented fiber nibwith many channels.

The aluminum flakes are dispersed initially in water and binder ofstarch with the pH adjusted anywhere between 7.0 and 8.0. This preventsthe build up of hydrogen gas, which is a notorious and dangerous problemassociated with aluminum pigments. The finished ink system is adjustedto a pH of 7.5 to 8.5; this is to ensure this problem does not occur.

The dispersion used in the present invention is of the type StapaHydrolac AW from Eckart and Roto Vario from Eckart. The amount needed toimpart a metallic look varies from about 10% to 25% by weight dependingupon the desired intensity of the color.

It is very interesting to note that on black surfaces, the pigmentedcolor and the aluminum pigments bond together to impart a uniformmetallic line. On white paper, the color is separated from the metallicflakes showing a line that is tinted in color and flecked with aluminumto impart a silver appearance.

The aluminum dispersions of the present invention are very stable attemperatures of 100° F. to 125° F. and do not dry up easily. Thiscontributes to the long shelf life of the marker. For this ink system tobe stable, the starch which bonds the aluminum flakes in the dispersionhave even more cohesion with the marker binder of the system therebycontributing to it staying in solution and keeping the aluminum flakessuspended.

The binder in the present invention is an acrylic resin solution ofabout 40% to 50% solids. This binder forms a clear film at roomtemperature on drying. It is resistant to water and adheres well to mostsurfaces. The pH is between 7.5 and 8.5. The viscosity is 100 to 150 cpsand the glass transition temperature t.g. °C.30. The binder must be ableto form a film at room temperature. This is the only way the aluminumflakes will bond to writing surfaces on drying. Typical resins of thistype include GA-1590 from B.F. Goodrich and Joncryl 537 from S.C.Johnson.

Many other polymers will come to mind of those skilled in the art. Thebinder is used at about 10% to 25% by weight depending on the desiredresistance properties.

The pigmented colored dispersion is of great importance since thisdispersion imparts the desired color to the overall metallic ink systemand makes it pleasing to the eye. The present invention utilizes adispersion of about 35% to 45% solids, pH 8.0 to 9.0, and viscosity of100 to 150 cps at 25° C. The pigments are grounded in an acrylic binderor surfactant to a particle size less than 0.5 micron enhancing theirbonding ability to the aluminum pigments. Common dispersions used in theinvention include Heucosperse colors from Heucotech and Acroverse colorsfrom Penn Color. A percentage of 10% to 20% by weight is used dependingon the desired color intensity.

The anti-settling agent additive is of particular importance because ofthe aluminum flakes readiness to settle out. The ionicly charged siteson the additive bond themselves to the aluminum flakes suspending themin solutions for extended periods and keeping them tightly adhered tothe surfaces of the colored pigments. This ensures that the inktraveling down the polyester filler into the nib and onto the writingsurfaces is metallized. Without the anti-settling agent, the aluminumflakes would separate very quickly from the colored pigments. Theresulting system will be one that writes very non-uniform by, withcolored lines appearing with no metallic appearance. The anti-settlingagent utilized in this invention is ionic in nature and derived from apolycarboxylic acid. Examples are phtalic acid, adipic acid andtri-metallic acid. A percentage of 0.25% to 1.5% by weight is utilized,an example of this agent is BYK105 from Byk Chemie.

A humectant is utilized in this invention to keep the finished writinginstrument from drying out on extended storage in warm and humidconditions. Polyglycols are particularly adept in these applications,although glycerin may be utilized. This invention uses Polyglycols ofmolecular weight of 400 to 725 at about 5% to 10% by weight. Examplesare Carbowax 400 and Carbowax 700 distributed by Pride Chemicals.

With many water based ink systems the surface tension is very high. Asurfactant helps reduce this property so that proper flow through thefiller and wetting on different surfaces are achieved. This inkcomposition has a surface tension of about 37 to 40 dynes/cm andutilizes a fluro chemical surfactant similar to one provided by 3MFC-170C and zonyl FSN supplied by DuPont Chemicals. A percentage of 0.5%to 0.75% by weight is used in this invention.

To discourage improper use of the marker, a water-soluble organicsolvent such as denatured ethanol is utilized in this invention. Thisalso contributes to its drying speed on different surfaces. An examplewould be SOF-642 distributed by Pride Chemicals. A quantity of 3% to 10%is utilized.

As mentioned before, the ink system needs to be maintained at a pH of7.0 to 8.5 so as to avoid the build up of hydrogen gas. Therefore, anamine pre-mixed with water to avoid shocking the aluminum flakes isutilized to adjust and stabilize the pH. This invention usesTriethanolamine (99%) at about 0.25% to 1.0% by weight, distributed fromPride Chemicals. Other common amines such as AMP-95 distributed by AngusChemicals can also be used.

Finally, a preservative is utilized to keep fungi and bacteria frombuild up in the writing instrument on extended storage. A number ofpreservatives will come to mind of one skilled in the art. The preferredproduct in this invention is Germaben II from ISP Polymers used at 1.0%to 3.0% by weight.

The following examples will demonstrate this ink system that utilizes asimple wick-style marker (FIG. 2).

All figures are percentage by weight.

Red Permanent Metallic Ink Distilled Water 57.00 B.F. Goodrich GA159410.00 Pride Chemical Carbowax 400 5.00 Eckart Stapa Hydolac AW 15.00Penn Color Acroverse Red 5123 10.50 ISP Polymers Germaben II 1.25 PrideChemical Triethylanolamine 99% 0.25 Byk Chemie Byk 105 1.00 100.00 BluePermanent Metallic Ink Distilled Water 42.25 B.F. Goodrich GA1594 10.00Pride Chemical Carbowax 400 5.00 Eckart Roto Vario RV5000 25.00 HeubackHeucosperseBS5525 15.00 ISP Polymers Germaben II 1.25 Pride ChemicalTriethylanolamine 99% 0.50 Byk Chemie Byk 105 1.00 100.00 GreenPermanent Metallic Ink Distilled Water 50.25 S.C. Johnson Joncryl 53711.00 Pride Chemical Carbowax 400 4.00 Eckart Roto Vario RV5008 20.00Penn Color Acroverse Green 32G120 12.00 ISP Polymers Germaben II 1.25Angus Chemical AMP-95 0.25 Byk Chemie Byk 105 1.25 100.00 Gold PermanentMetallic Ink Distilled Water 44.50 S.C. Johnson Joncryl 537 10.00 PrideChemical Carbowax 400 7.00 Heubach Heucosperse III YS5345 15.00 EckhartRoto Vario RV5008 20.00 ISP Polymers Germaben II 2.00 Angus ChemicalAMP-95 0.25 Byk Chemie Byk 105 1.25 100.00

Semi-Permanent Wet Erase Metallic Ink For Black and White Melamine,Porcelain and All Non Porous Boards

Blue Ink Wet Erase Metallic Distilled Water 63.75 Pride ChemicalCarbowax 400 7.00 ISP Technologies PVP/VA630 2.00 Heubach Heucosperse33S5528 10.00 Eckhart Roto Vario RV5008 15.00 ISP Technologies GermabenII 1.00 Angus Chemical AMP-95 0.25 Byk Chemie Byk 105 1.00 100.00 RedInk Wet Erase Metallic Distilled Water 67.75 Pride Chemical Carbowax 4004.00 Penn Color Heucosperse Red 5123 15.00 ISP Technologies Germaben II1.00 Eckart Roto Vario RV5308 10.00 Pride Chemical Triethanolamine 99%0.50 Byk Chemie Byk 105 0.75 ISP PVP/VA 670 1.00 100.00

Summarizing, the present invention comprises a metallizing system forwriting instruments having a densely packed polyester fiber reservoirand a porous polyester oriented fiber nib with channels allowing passageof specific particle size aluminum pigment (less than 12 microns). Thisnib is in contact with the reservoir shown in the writing instrumentillustrated in FIG. 2 and the system functions by capillary action.

As described, the ink system includes: distilled water as a carrier, atabout 40% to 70% by weight; a water soluble organic solvent having anevaporation rate greater than 1.0 at 25° C. using butyl acetate at about1.0 as a basic; a liquid acrylic resin solution at about a 40% to 50%solids and present in the ink system from about 10% to 20% by weight;said humectant being selected from a group of polyglycol molecularweight 400 to 1025 and present in the ink system from about 5% to 15% byweight; an aluminum pigmented dispersion of about 10% to 15% solids atless than about 12 microns particle size and present at 10% to 25% byweight with a pH of about 7.0 to 8.5; a fluro chemical surfactant with apH of about 9.0 and surface tension of about 25 dynes/cm and present at0.25% to 1.0% by weight; an anti-settling agent chosen from a lowermolecular weight unsaturated polycarboxylic acid that has an ioniccharge present in an amount 0.25% to 1.25% by weight; and an ammoniacalbase for adjusting the pH of the ink system to about pH 7.5 to 8.5present in an amount 0.25% to 1.5% by weight; and a colored water-basedpigmented dispersion of about 35% to 45% solids having a particle sizeless than about 0.5 microns and present in amount 10% to 20% by weight.

The ink system also includes a binder than is an acrylic resin solutionpresent at about 10% to 25% by weight selected from a group or class ofacrylic resin solutions that have a t.g. °C. −16 to 30, MFFT °C.<25° C.,a viscosity of about 50 cps to 150 cps, and a solid content of about 40%to 50%.

Although the present invention has been described in relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art. It ispreferred, therefore, that the present invention be limited not by thespecific disclosure herein, but only by the appended claims.

What is claimed is:
 1. A writing instrument, comprising: a denselypacked polyester fiber reservoir and a porous polyester oriented fibernib with channels allowing passage of an ink therethrough; an ink systemin the reservoir, the ink system including a color pigmented dispersionand a metallic dispersion pigment of a particle size that is not greaterthan about 12 microns; an anti-settling agent to keep the particles ofthe metallic dispersion in suspension; and the fiber nib being incontact with the reservoir and being able to absorb the metallicdispersion by capillary action without a valve-action mechanism.
 2. Thewriting instrument of claim 1, including; a nonvolatile humectant; andsaid color pigmented dispersion having a sub-micron particle size. 3.The writing instrument of claim 2, wherein said ink system includes:distilled water as a carrier, at about 40% to 70% by weight; a watersoluble organic solvent having an evaporation rate greater than 1.0 at25° C. using butyl acetate at about 1.0 as a basic; a liquid acrylicresin solution at about a 40% to 50% solids and present in the inksystem from about 10% to 20% by weight; said humectant being selectedfrom a group of polyglycol molecular weight 400 to 1025 and present inthe ink system from about 5% to 15% by weight; an aluminum pigmenteddispersion of about 10% to 15% solids at less than about 12 micronsparticle size and present at 10% to 25% by weight with a pH of about 7.0to 8.5; a fluro chemical surfactant with a pH of about 9.0 and surfacetension of about 25 dynes/cm and present at 0.25% to 1.0% by weight; ananti-settling agent chosen from a lower molecular weight unsaturatedpolycarboxylic acid that has an ionic charge present in an amount 0.25%to 1.25% by weight; and an ammoniacal base for adjusting the pH of theink system to about pH 7.5 to 8.5 present in an amount 0.25% to 1.5% byweight; and a colored water-based pigmented dispersion of about 35% to45% solids having a particle size less than about 0.5 microns andpresent in amount 10% to 20% by weight.
 4. The writing instrument ofclaim 3, wherein this said ink system is stable in a slightly alkalinemedium and non-reactive with hydrogen gas, and said surfactant iscapable of reducing surface tension and promote flow.
 5. The writinginstrument of claim 2, wherein said ink system has one phase with aviscosity of 5 cps to 10 cps, a pH of about 8.0 to 8.5, and a surfacetension of about 37 dynes/cm, which lays down a smooth unbroken opaquemetallic line.
 6. The writing instrument of claim 2, wherein this saidink system includes a binder that is an acrylic resin solution presentat about 10% to 25% by weight selected from a group or class of acrylicresin solutions that have a t.g. °C. −16 to 30, MFFT°C.<25° C., aviscosity of about 50 cps to 150 cps, and a solid content of 40% to 50%.7. The writing instrument of in claim 5, wherein said binder forms aclear film at room temperature and remains stable at temperatures 100°F. to 125° F. for extended periods to allow for a longer shelf life ofthe ink system.
 8. The writing instrument of claim 2, including a bindercomprising a polyvinylpyrrolidone polymer at about 1% to 2% by weight,so as to complete a semi-permanent wet erase and/or dry erase metallicink system capable of writing on black and white melamine, porcelain andall non porous boards.
 9. The writing instrument of claim 2, whereinthis ink system comprises an aluminum-pigmented water-based dispersionwhose particle size is no greater than 12 microns made from brightleafing aluminum flakes.
 10. The writing instrument of claim 9, whereinsaid aluminum is dispersed in a medium of starch and water to preventsettling and a pH of 8.0 and 8.5 to prevent hydrogen gas build up and isstable at 100° F. to 125° F. so as to prevent drying out of the writinginstrument.
 11. The writing instrument of claim 2, wherein said inksystem includes, as a an anti-settling additive based on a lowermolecular weight, unsaturated polycarboxylic acid with ionic activitythat will bond with aluminum pigments and keep them in suspension forextended periods in a low viscosity ink system.
 12. The writinginstrument of claim 2, wherein this said anti-settling additiveincreases color strength and prevents hard settling of aluminumpigments.
 13. The writing instrument of claim 2, wherein this said inksystem utilizes a humectant chosen from a group of polyglycol ofmolecular weight 400 to
 1025. 14. The writing instrument of claim 2,wherein this said ink system, includes a preservative to prevent buildup of fungi and bacteria in water-based inks containing diazolidinylurea, methyl paraben, and propyl paraben.
 15. The writing instrument ofclaim 2, wherein this said ink system includes a pH adjuster in the formof a base capable of stabilizing said system to a pH of 8.0 to 8.5. 16.The writing instrument of claim 2, including a polyester fiber reservoirthat is tightly bonded in a wrapped polypropylene skin in contact with amulti-channel highly porous oriented fiber nib containing said inksystem, said ink system having a viscosity of 5 cps to 10 cps at 25° C.,a surface tension of less than 40 dynes/cm at 25° C., a pH about 7.0 to8.5 capable of making permanent or semi-permanent metallic lines onblack and white surfaces.
 17. The writing instrument of claim 2, whereinsaid instrument is capable of making semi-permanent opaque metalliclines on human skin and nails that are washable with soap and water. 18.A writing instrument, comprising: a non valve-action body defining anink reservoir with an opening that is closed off by a fiber nib; and anink system in the reservoir, the ink system containing an aluminumpigmented dispersion of not greater particle size than about 12 microns,a sub-micron pigmented colored aqueous dispersion to impart a tint, ananti-settling agent to keep aluminum particles from settling out, and abinder to bind the aluminum pigments together.
 19. The writinginstrument of claim 18, further including a preservative, a surfactantto reduce surface-tension, and a pH adjuster.
 20. A method for formingtemporary tattoos on human skin, comprising the step of: providing awriting instrument which includes a densely packed polyester fiberreservoir and porous polyester oriented fiber nib with channels allowingpassage of an ink therethrough, an ink system in the reservoir, the inksystem including an aluminum pigment of a particle size that is notgreater than about 12 microns, and the fiber nib being in contact withthe reservoir and being able to absorb the aluminum pigment by capillaryaction; and movingly pressing the writing instrument against human skinto create temporary tattoos that are in the form of semi-permanentopaque metallic lines.
 21. A writing instrument, comprising: a denselypacked polyester fiber reservoir and a porous polyester oriented fibernib with channels allowing passage of an ink therethrough; an ink systemin the reservoir, the ink system including a color pigmented dispersionand an aluminum pigment of a particle size that is not greater thanabout 12 microns; an anti-settling agent to keep the aluminum particlesin suspension; and the fiber nib being in contact with the reservoir andbeing able to absorb the aluminum pigment by capillary action without avalve-action mechanism.